Researchers use yeast to help piece together human genome sequence jigsaw

Nov 17, 2011

Using yeast as a model, a team of Spanish researchers has made predictions about how individuals differ from one another by analysing genome sequences.

Writing in the journal Nature Genetics, the researchers emphasise that their findings have important implications for the future of personalised medicine. If scientists can better understand which genes are important to a particular process, it is easier to make accurate predictions about an individual's biological make-up.

We are all made up of over 20,000 genes, and in each of us, several thousand of these genes carry mutations. Scientists don't yet know what happens when most human genes are altered, which means they can't yet make any predictions about human health based on genome sequence. In practice, this means that for most common human diseases, which genes are important is something that remains unknown. Consequently, a scientist can't tell whether an individual will develop a condition based on his or her DNA sequence.

To confront this problem head on and assess whether it is possible to make useful predictions about the biology of individuals, the Spanish researchers carried out tests on budding yeast, a species commonly studied as a 'model organism' by researchers the world over.

'The key point is that in a model organism, we can test how good our predictions are. We have a much better idea of the genes that are important for each process, and so we can really test whether we can make useful predictions about the biology of individuals, such as whether they are affected by a drug,' says one of the study authors, Ben Lehner from the Centre for Genomic Regulation (CRG) in Barcelona, Spain. 'In yeast we can make predictions, and then we can use a large number of fast and cheap experiments to test whether these predictions are correct. This is very important - to be able to experimentally test how well prediction methods actually work.'

The team evaluated predictions about the phenotypes of 19 varieties of yeast. The first challenge the Spanish researchers faced was determining which of the approximately 3,000 mutated genes in each organism are actually altered. They then needed to predict whether each individual was likely to be abnormal for a particular phenotype such as growth in a different environmental condition.

The study results show that there are at least two necessary conditions for such predictions to be made: good knowledge about which genes are important for a phenotype, and experiments performed on individuals under controlled conditions to evaluate how accurate the predictions are. As this remains tricky in humans due to the many different variables involved, and the fact that most genes that affect particular phenotypes and diseases remain unidentified, the team stress the importance of carrying out further studies on simple model organisms like budding yeast.

'The most important thing is to have comprehensive knowledge about the genes that are important for a particular phenotype. It is not possible to predict accurately if we only know a subset of the genes that are important,' says another study author, Rob Jelier, also from the CRG. 'However, we found that, when our understanding of gene function is good, quite accurate predictions can be made using a surprisingly simple genetic model. This provides some hope for the future of personalised and predictive medicine in humans.'

Although it has been many years since the human genome was first mapped, there are still many genes whose function we do not understand. Researchers from the University of Gothenburg, Sweden, and the University of Toronto, ...

Researchers have taken a major step towards understanding the language of gene regulation in the fruitfly Drosophila and they expect the technique to be rapidly applicable to understanding the effects of genome variation ...

If you think yeast is most useful for beer and pizza crust, here's something else to chew on: a team of U.S. researchers has identified and compared the genetic codes for all known species of yeasts closely related to bakers' ...

The most detailed analysis to date of how humans differ from one another at the DNA level shows strong evidence that natural selection has shaped the recent evolution of our species, according to researchers from Cornell ...

In recent years, genetic studies have uncovered hundreds of DNA variations linked to common diseases, such as cancer or diabetes, raising the prospect that scientists can gauge disease risk based on information ...

Recommended for you

UCLA life scientists have created an accurate new method to identify genetic markers for many diseases—a significant step toward a new era of personalized medicine, tailored to each person's DNA and RNA.

Similar to humans and animals, plants possess an innate immune system that protects them from invading pathogens. Molecular structures that only occur in pathogens enable their recognition and trigger the ...

A new study into the generalist parasite Albugo candida (A. candida), cause of white rust of brassicas, has revealed key insights into the evolution of plant diseases to aid agriculture and global food security.

User comments : 0

Please sign in to add a comment.
Registration is free, and takes less than a minute.
Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.

Javascript is currently disabled in your web browser. For full site functionality, it is necessary to enable Javascript.
In order to enable it, please see these instructions.